Effect of maintaining apical patency with a CM instrument on apical transportation and centering ability

TL;DR

This study examined how maintaining apical patency affects the performance of a CM instrument in root canals using CBCT imaging.

Contribution

The study provides empirical evidence on the impact of apical patency on apical transportation and centering ability in root canal instrumentation.

Findings

Maintaining apical patency had no significant effect on apical transportation.

Centering ability was significantly influenced at specific measurement levels.

The B2 group showed better centering ability compared to the A2 group at 0.5 mm short of the foramen.

Abstract

The aim of this study was to assess the impact of the apical patency technique on apical transportation and centering ability of a controlled memory (CM) instrument in the apical region using cone-beam computed tomography (CBCT). Sixty distobuccal canals of extracted maxillary molars were assigned to three groups (n = 20) based on the patency length achieved using the Easy ProDesign Logic (EPL) 25.01 file: Group A — 1 mm beyond the apical foramen; Group B — at the apical foramen; and Group C — 1 mm short of the apical foramen (no patency). Each group was then subdivided into two subgroups (n = 10) according to the working length used for root canal preparation with the EPL 25.05 file: A1, B1, C1-I, and C1-II — 1 mm short of the apical foramen and A2, B2 — at the apical foramen. CBCT images were acquired at three time points: pre-patency, post-patency, and post-instrumentation. The scanned images were analyzed using the E-VOL DX software. No statistically significant difference in apical transportation was found between the groups after patency or after instrumentation (p < 0.05), irrespective of the measurement levels (0.5, 1, and 2 mm short of the apical foramen). A significant difference in the centering ability of the patency instrument was observed only at 2 mm short of the foramen (p < 0.05). The B2 group exhibited a higher centering ability, with a statistically significant difference compared to the A2 group (p < 0.05), observed only at 0.5 mm short of the foramen. In conclusion, maintenance of apical patency using the EPL instrument had no influence on apical transportation; however, it may slightly affect the centering ability of the root canal.

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